To have students be able to demonstrate an understanding of electricity, the flow of electrons, being the fundamental force involved in atoms changing what they're bound to in a chemical reaction.
Concepts to cover (cross-referenced to the CCI mind map of concepts)
electrochemistry, alloys
Time-allotment breakdown/schedule
1. Review last session's activity in notebook. (10min)
2. Lead into the idea of creating electricity from chemical reactions from last time, then go into driving reactions using electricity. Go into set up of battery powered electroplating of coins. (10min) 3. Run first electroplating activity. (40min) 4. Talk about how electricity was used to pull metals out of solution and onto other metals. Now bring up the question of chemical reactions producing their own electricity to make a new reactions. Lead into the Copper to Silver to Gold reaction. (10 min) 5. Run Copper to Silver to Gold reaction. (40min) 6. Review and cleanup. (10min)
Materials/supplies to gather
1. For the Copper to Silver to Gold penny electroplating lab: Zinc granules (Paul) NaOH solution (Paul) pre-1982 pennies (Paul/Levi) tweezers (Paul) 3 hot plates (Levi) Extension cords (Ben)
2. For battery powered electroplating of coins: 1-1.5 v power source (old batteries preferred) Alligator clips (Ben) small, non-conductive, disposable container (Paul) Acetic acid (Paul) two or more pennies (Levi) quarters, nickles and dimes (Levi) plastic wrap (Ben)
Introductory points
Safety warnings/instructions
Hazardous materials: NaOH and hot plates.
Need: Goggles, gloves, tweezers.
-Metals can conduct electricity.
-Adding or subtracting away electrons from metals allow for them to change what they are bonded to.
-Chemical reactions can be used to make electricity, and electricity can be used to drive chemical reactions.
Facilitation questions/approaches and advice to mentors
Additional facilitation questions for the Copper to Silver to Gold penny electroplating lab-What could we use instead of the battery as an energy source? (The sun! A solar panel)-Why do we need a battery for electroplating when we didn't need a battery for the lemon to produce electricity? (This chemical reaction takes more energy and we want it to happen faster, so we needed a power source.) Additional facilitation questions for battery powered electroplating of coins:-should move the 2nd "check for understanding" point to this section, as it follows more closely to this activity-What about the brass penny? Will the inside be gold like the outside or a different color? Will it be the same color as the inside of the zinc coated, silvery penny? (Inside will be brown because its copper, the same interior as the zinc coated penny, because we only changed the outside)
Clean-up instructions
Wrap up points
Check for understanding
-What is electroplating? Why do the metals need to be placed in a liquid?-What happens to metal to allow for them to dissolve in a liquid? What needs to happen to them when they come back out of the liquid?-Why do we need a power source like batteries sometimes for our reactions to happen? (Some reactions need more energy than others)-Did we have an extra 'power source' for the second activity? Did you have to add extra energy for the reaction to take place? Think about the temperature! (Yes! We had to heat the reaction to make it happen. Heat is a form of energy but not as powerful as the electricity directly from an outlet.)
Solar Army
CCI Solar Curriculum
Electroplating9Mar2013
2. Lead into the idea of creating electricity from chemical reactions from last time, then go into driving reactions using electricity. Go into set up of battery powered electroplating of coins. (10min)
3. Run first electroplating activity. (40min)
4. Talk about how electricity was used to pull metals out of solution and onto other metals. Now bring up the question of chemical reactions producing their own electricity to make a new reactions. Lead into the Copper to Silver to Gold reaction. (10 min)
5. Run Copper to Silver to Gold reaction. (40min)
6. Review and cleanup. (10min)
Zinc granules (Paul)
NaOH solution (Paul)
pre-1982 pennies (Paul/Levi)
tweezers (Paul)
3 hot plates (Levi)
Extension cords (Ben)
2. For battery powered electroplating of coins:
1-1.5 v power source (old batteries preferred)
Alligator clips (Ben)
small, non-conductive, disposable container (Paul)
Acetic acid (Paul)
two or more pennies (Levi)
quarters, nickles and dimes (Levi)
plastic wrap (Ben)
Need: Goggles, gloves, tweezers.
http://www.chymist.com/copper%20silver%20gold.pdf
2. For battery powered electroplating of coins:
http://www.instructables.com/id/Clean-and-Simple-Electroplating/?ALLSTEPS
-Adding or subtracting away electrons from metals allow for them to change what they are bonded to.
-Chemical reactions can be used to make electricity, and electricity can be used to drive chemical reactions.
Additional facilitation questions for battery powered electroplating of coins:-should move the 2nd "check for understanding" point to this section, as it follows more closely to this activity-What about the brass penny? Will the inside be gold like the outside or a different color? Will it be the same color as the inside of the zinc coated, silvery penny? (Inside will be brown because its copper, the same interior as the zinc coated penny, because we only changed the outside)